Method and apparatus for remotely controlling radio receiving systems



Dec. 3, 1929. W.T. POWELL 1,733,262

METHOD AND APPARATUS FOR REMOTELY CONTROLLING RADIO RECEIVING SYSTEMS Filed oct- 1 1 925 5 Sheets-Sheet 1 muviu w m0 mzora INVENTOR'- wmraw "r. POWELL ATTORNEY Dec. 3, 1929, w. T. POWELL METHOD AND APPARATUS FOR REMOTELY CONTROLLING RADIO RECEIVI NG SYSTEMS Filed Oct. 15, 192$- 3 Sheets-Sheet 2 INVENTOR WINFRED T POWELL BY A).

ATTORNEY Dec. 3, 1929. T. POWELL A 1,738,262

METHOD AND APPARATUS FOR REMOTELY CONTROLLING RADIO RECEIVING SYSTEMS Filed Oct- 1 1925 KSheets-Sheet 3 MOTOR FIG. 4

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BY 2" i ATTORNEY FIETHOD AND APPARATUS FOR REMOTELY CONTROLLING RADIO RECEIVING SYSTEMS- Patented UNITED STATES ,GARLSON- TELEPHONE MANUFACTURIN CORPORATION or NEW YORK This invention relates to radio receiving systems and more particularly to such systerns to be used in radio'b'roadcasting.

At the present time radio equipment for the reception'of broadcast programs is located in the'best rooms of the home with the consequent requirement that it must be care P fully designed and finished to harmonize with the other furniture of the room in which it is placed. At this time it is also necessary for theoperation of the set, to employ sources of energy in which certain harmful acids take some-part, with the result that the floors andrugs may be damaged thereby. v

It is frequently desirable to have the received program reproduced in different rooms of the home,- but to accomplish this' result, it is necessary to employ a long cord between the receiver and the loud speaker, so that the loud speaker may be carried to any desired \room and when it becomes necessary to change the adjustment of the radio set, in order to bring in another program, it is necessary to walk to the room'in which the receiver is located.

In accordance with the present invention it is proposed to employ an arrangement, by which a radio receiyer located at adistant point may be remotely controlled. Such an 30 arrangement permits the radio receiver to be housed in an inexpensive cabinet located in the cellar or attic and in addition to this, the most efficient arrangement of parts from an engineering and maintenancestand-point he set'harmonrecei-ving-system may be selectively adjusted from a remote point and whereby the accuracy of such adjustment maybe readily checked." I

additional feature of the invention rei sides in the provision of a remotely controllet} radio receiving system having'a plurality 0 may beemployed' without anfyt considerations I PATENT OFFICE WINFRED '1. POWELL, OF ROCHESTER, NEW YORK, ASSIGNOE TO THE STROMBEBG- GOOMPANY; OF ROCHESTER, NEW YORK, A

A Application fil ed October- 15, 1925. Serial No. 62,611.

outlets remotely placed with respect to each other and having means associated with each of said outlets whereby the radio receiving system may be selectively adjusted.

A further feature of the invention includes 'a radio receiving system arranged to be selectively adjusted from any one of several control stations and in which one station is given preference over another, that is, one station may selectively adjust the radio receiving system to the exclusion of the remaining station or stations.

These and other features will appear from the detailed description and appended claims.

Referring to the drawings, Fig. 1 diagram-' matically represents a multi-stage tuned radio-frequency radio receiver of which only the last audio stage is shown indetail. Near I the center of this figure, thereis shown remotely controlled mechanism associated with the radio receiver, by which the various tuning adjustments are effected. At the right of the dotted line, there is indicated the loud speaker or reproducer, preferably of the portable type, having associated therewith means for controlling the adjusting mechanism associated with the radio receiver.

Fig. 1 is a siiiiplified showing of the circuits of Fig. l. v

Fig. 2 is a view of the controlling means located atthe loud speaker.

Fig. 3 represents the controlling mechanism located at'the radio set.

Fig. 4 is a slightly modified form of the invention of Fig. 1 in which. a Wheatstone bridge arrangement controls the setting of the radio set.

Fig. 4 is. a simplified showing of the cir- I cuitsof Fig. 4. I

Referring to Fig. 1-, 5 represents a multistage tuned radio-frequency amplifier and detector, in which a single tuning shaft 24 (Fig. 3)'i;s employed for varying the adjustment of the tuning condensers of the several stages and detector. The output circuit of fthedetector is electrically connected to the "input circuit of an audio amplifier, the

vacuum tube of which is designated 6. VVellknown A and B batteries designated 7 and 8 are employed to" supply suitable operating energy for the several vacuum tubes. The

' remote control equipment is to be employed,

the B battery is connected from its positive pole, by conductor 9, normal contacts of the jack J through the impedance coil 10, conductor 11, and normal contacts of the jack J to the plate of the vacuum tube. The signal energy in the output circuit, however, is transmitted to the remotely located loud speaker 17 through condenser 12, conductor 13, tip 14 of the jack J and tip 15 of the plug P, to the condenser 16 and the loud speaker 17 through the ring contacts of the" plug and jack as mentioned, condensers 18 and 19 in seriesto the plate circuit previously referred to. In this portion of the description, it has been assumed that the radio receiver was previously tuned to receive the desired program.

It will now be assumed that it is desired to change the tuning of the radio receiver, by means of remote control. In order to accomplish this result, a rheostat 20 controlled by a dial 21 (Fig. 2) or other suitable adj usting means is. located adjacent the loud speaker or may be mounted in the base thereof, to provide a compact portable device. On the shaft of the rheostat there may be mounted a stations indicator 60, which is in the form of a cylinder, on the periphery of which there is space for making a record of the adjustments necessary for receiving various stations. To bring about the desired adjustment of the remotely located radio receiver, the dial 21,is rotated to adjust the arm 23 of the rheostat 20.

It has been pointed out that the radio receiver, which has several stages, is preferably tuned to the frequencyof the incoming signal by condensers mounted on the same shaft, such as 24, -which shaft; may be rotated I throughgear 61 and worm 62 by a dial 25,

when the receiver is not remotely controlled or by a motor 26 when the remote control arrangement is employed. The shaft of motor 26, it will be understood, is provided with a worm drive member 27 cooperating with gear 28 to perform the same adjustment accomplished manually by the dial 25. It will be understood that the pitch of the worm 27 is such that when the dial 25 is turned either to the right or to the left the gear-28 cooperating with this worm may likewise turn the motor 26. If desired suitable clutch mechanism may be provided whereby the gear dial 25 is opthe; gear 28 turns on its shaft. However,

when the motor 26 is operated, the gear 28 frictionally engages the shaft to turn it since the load on this shaft is not great enough to overcome the mentioned frictional engagement of gear 28 with its shaft.

In order to cause the motor 26 to turn the shaft 24 in either direction, suitable controlling circuits are located at the receiver and are represented between the dottedlines in Fig. 1, while the remote control equipment at the loud speaker is shown at the right of this figure. The controlling circuits include a relay 29, the resistance of whose winding D is equal to the resistance of the right hand winding A, plus the resistance of the coil X, at the loud speaker. When the resistance B of the rheostat 20 is equal to the resistance C of the rheostat 30 at the radio set, there will be an equal potential drop across each winding of the relay 31, since the resistance of winding D is equal to the resistance of the winding A, plus the resistance of coil X, previousl described. The relay 31 is a polarized di erential relay, so that under the conditions just stated, it will not move its armature in either direction, because the current throughone winding is equal to and opposite to that of the other. If the resistance B at the rheostat 20 is increased by turning the dial 21 in a clockwise direction, the

potential drop across the upper winding of relay 31 is increased and its armature is operated in one direction, for example, to the left. This will close a circuit for the winding of relay 32, whereas, if the resistance B of rheostat 20 is decreased by turning the dial 21 in a counter-clockwise direction, the potential drop across the upper winding of relay 31 is decreased and its armature is moved to the right to close a circuit for the winding of relay 33. With the relay thus operated, a circuit is closed for operating the motor 26 in such a direction that it increases the resistance of rheostat C and when a sufiicient amount of such resistance is added, 1

so that the resistance of B is equal to G, relay 31 is restored to its normal position and the motor 26 is stopped with the radio set ad justed to receive the desired program.

When the relay 33 is operated, a circuit is closed for operating the motor26 in such a direction that the resistance of C is reduced and when it is reduced to a point where it equals the resistance B of rheostat 20, relay 31 is restored to its normal condition and the motor 26 is stopped.

It will be noted that the output circuit of the radio set is connected through-the condensers, 12, 16,18 and 19 tothe loud speaker and thesecondensers are of suiiicient capacity to transmit audio frequency signals efiectlve- 1y. The coil 10, which is bridged across theoutput circuit allows the plate current from the plate battery 8 to be connected to the The broken leads and 36 indicate that the output circuit may be connected in 111111131 plc to other jacks locatedin various rooms of the home, so that the loud speaker may be carried from one room to another andconnected to any of these jacks to receive the program-in the room desired.

' Fig. 1 is a schematic showing of the'circuit arrangementof Fig. 1 with certain parts such as motor 26 omitted.

Fig. 4 shows a modified form. of the invention in which a' Wheatstone bridge controlling arrangement is used. The parts of the circuits of Fig. 4, which are the same as- I corresponding parts of Fig. 1 have been desamount of resistance introduced into their associated bridge arms. Increasing the re-- ignated by the same reference characters.

The impedance coils, rheostats and relays of this arrangement are for the same purposes as similar parts in the circuits of Fig. 1. Re-

ferring to the schematic arrangement,shown in Fig. 4, it will be seen that by making the direct current resistance of A equal to D* and U equal to X, the bridge will be balanced and no current will flow through relay 31, when the rheostats B and C have the same sistance B, by means of the dial 21, causes the relay 31 to operate in the proper direction to rotate the motor 26 in such a direction that more resistance C of the rheostat 30 is introduced" into the bridge. The decreasing of the resistance B at the remote control stage will cause the relay 31 to operate in the opposite direction, which causes the motor to reverse and to reduce'the resistance'C. It will thus beseen that the stations indicator at the receiver "set will follow the stations indicator at the loud speaker. In the present modification, the relay 31 is a single wound polarizedrelay, instead of being a difierentially wound polarized relay, as shown in Fig. 1. 1

In the systems of Figs. 1 and 4 the circuit arrangement including the 'jacks or outlets J and J, is so arran ed that when a program is beingreceive through jack or outlet J the other jacks or outlets are disabled. Since with-the plug'fP inserted in jack J the controlling network ,for'the relay 31, is interrupted at the outermost, right hand set of contacts at this jack. In this way .jack

or outlet J is given preference over the other outlets of the system.

The-construction of relay 31' may be similar to that described in the Journal of the A. a

I. E; E. for March, 1925, in a paper by Fry and Gardner, which is sufliciently sensitive to 0perate on reversals of current as low as 1 milliampere.

What claim is: v 1. In a radio receiver, detecting means hava variable tuning device, a vacuum tube amplifier associated with the output of said defier having a. signal reproducer therein, mechanism for adjusting s'aidtuning device, an

electrically balanced circuit network for contecting means, an output circuit for said amplitrolling said mechanism, and means at aremote point for disturbing the electrical balance of said circuit network to set said mech; anism in operation. v f

2. Ina signaling system, a series of variably tuned circuits, tuning means for said circuits, mechanism for adjusting said tuning means, anelectrically balanced circuit ar- 'rangement for controlling said mechanism, means at a remote point for disturbing the v electrical balance of said'arrangement to-set said mechanism lnoperation, and means controlled by the operation of said mechanism to restore the balance of said arrangement whereby said mechanism is brought to rest.

3. In a signaling system, avariablytuned circuit, tuning means for said circuit, a'motor for o erating said tuning means, a Wheat-- stone rldg'e arrangement, one of whose arms includes a variably controlled device at a remote point to control the balance of said bridge and .to indicate a desired tuning "of said circuit, a relay connected across conjugate armsof said bridge, said ,relay'being operatedby the unbalance of said bridge, said motor being set into rotation bythe operation of said-relay, and means controlled by said motor to restore said balance for deenergizing said relay en a predetermined tun; ing of saidcircuit ifi accom'plished.

4.- In a signaling system, a radio receiverprovided with a tuning element, a motor for operating said tuning element, ,a signal -re-.

producer, located at a remote point, a pair of conductors for connecting said signalreroducer to said radio-receiver, aWheatstone each including a variable .impe ance, the imridge arrangement having a pa ir of fixed impedance arms and a second air of arms,

edance of one of said arms being adjusted 1 y the operation of-said motor, the other variable impedance being located at said Signal reproducer and being connected in series i 130.

with said pair of conductors, said last men:

tioned impedance being adjustable at will to disturb the balance ofsaid bridge, and means connected across conjugated arms of said bridge to set said motor in operationwhen said bridge is unbalanced, whereby said motor varies said first mentioned variable impedanceto restore the balance of said bridge, said means operating on the restoration of said balance to stop the operation of said motor.

5. In a signaling system, a radio receiver provided with a tuning element, a motor for operating said tuning element, a signal reproducer, located at a remote point, a pair of conductors for connecting said signal reproducer to said radio receiver, a Wheatstone bridge arrangement having a pair of fixed impedance arms and a second pair of" arms, each including a variable impedance, the impedance of one of said arms being adjusted by the operation of said motor, the other variable impedance being located at said signal reproducer and being connected in series with said pair of conductors, said last mentioned impedance being adjustable at will to disturb the balance of said bridge, and a relay having a balanced armature connected across conjugated arms of said bridge to set said motor in operation when said bridge is unbalanced, whereby said motor varies said.

first mentioned variable impedance to restore the balance of said bridge, said relay operating on the restoration'of said balance to stop the operation of said motor.

6. The method of remotely controlling a radio receiving system, which comprises establishing at a remote point an indication corresponding to a desired broadcasting station, automatically adjusting the tuning element of the radio receivin system in re-.

sponse to the establishing of said indication, to the frequency of the desired broadcasting station as indicated, and reproducing in discernible form at the remote point through said radio receiving system a signal trans mitted from said desired broadcasting station whereby the accuracy of the tuning of said radio receiving system with respect to the station indication may be checked.

7. The method of remotely controlling a radio receiving system, which comprises establishing at a remote point an indication corresponding to a desired broadcasting station, automatically adjusting the radio receiving system by progressive rotation of thetuning element thereof in response to the establishing of said indication, to the frequency-of the desired broadcasting station as indicated,

audibly reproducing at the remote point through said radio receiving system a signal transmitted from said desired broadcasting station whereby the accuracy of the tuning of said radio receiving system with respect to the station indication may be checked, and

regulating the volume of the reproducedsignal to prevent distortion thereof.

8. The method of remotely controlling a radio-receiving system which comprises establishing at a remote .point an indication corresponding to a desired broadcasting station, automatically adjusting the radio receiving system by an operation of the tuning element thereof in either direction of its movement in response to said establishment of the indication, to the frequency of the desi1'ed.broad casting station as indicated, and reproducing in audible form at a remote point through said radio receiving system a signal transmitted from said desired broadcasting station whereby the accuracy of the tuning of said radio receiving system with respect to the station indicatioii'may be checked.

9. In a radio receiving system, a plurality condition and indication, driving nleans directively controlled in response to the adjustment of said preselecting means for directively operating said common control to eii'ect a desired adjustment of said tuning means to a predetermined position, and a signal reproducer linked to said detecting network and within range ofsaidremote point for checking the accuracy of the adjustment of said tuning means.

10. In a radio receiving system, a plurality of radio amplifying networks and an associated detecting network linked together in cascade, tuning means for at least one of said networks, adjustable selecting means at a remote pointjor establishing a desired station selection condition and indication, driving means reversibly controlled in response to the adjustment of said selecting means for directively adjusting said tuning means, and a signal reproducer linked to said detecting network and within range of said remote point for checking the accuracy of the adjustment of said tuning means.

11. In a radio receiving system, a plurality of radio amplifying networks and an associated detecting network linked together in cascade, tuning means for certain of .said networks, a manual control at said networks for selectively setting said tuning means, adjustable preselecting means at a remote point for establishing a desired station selection condition and indication, reversible driving means directively controlled in response to the adjustment of said preselecting means for ,directively adjusting said tuning means, and

12. In a radio receiving system, a plurality of radio amplifying networks and an associatcd detecting network linked together in cascade, tuning means for at least one of said' networks, rotatably adjustable preselecting means at a remote point for establishing a desired station selecting condition and indication, reversible driving means directively controlled in response to the adjustment of said preselecting means and out of step therewith for dircctively setting said tuning means, and a signal reproducer linked to -said detecting network and within. range of said remote'point for checking the accuracy of the adjustment of said tuning means.

13. In a radio receiving system, a plurality of radio amplifying networks and an associated detecting network linked together in cascade, tuning means for certain of said networks, an output circuit linked to said detect ing network having a plurality of remotely placed outlets, means directively controlled through any of said outlets for selectively adjusting said tuning means, and signal reproducers connectible to said output circuit through said outlets whereby the adjustment of said tuning means may be checked.

14. .In a radio receiving system, a plurality of radio am lifying networks and an assocascade, tuning means for certain of said networks, adjusting means for .said tuning means, an output circuit linked to said detecting network having a plurality of outlets remotely placed with respect to each other, means associated with each of said outlets for selectively controlling said adjusting means, signal reproducers connectible to said output circuit through said outlets whereby the adj ustment of said tuning means may be checked, and means at one outlet for preventing adjustment of said tuning means from a second outlet. v

15. In a radio receiving system, a plurality of radio amplifying networks and an associated detector network linked together in cascade, tuning means for certain of said networks an output circuit linked to said detector network having a plurality of outlets re- .motely placed with respectto each other, controlling means-associated'with each of said outlets for selectively adjusting said tuning means, the controlling mean's associated with certain of said outlets-including a series coni-tIOlCll'Clllt governed at one of said outlets,

- means at said 'last mentioned outlet for disciated detecting network linked together in' tion condition, driving means directively con trolled in response to the adjustment of said selecting means and following the movement thereof for directively adjusting the tuning means, and a signal reproducer linked to said detecting network and within range of said remote point for checking theaccuracy of the adjustment of said tuning means.

17. In a radio receiving system, a radio receiver including an output circuit, tuning means for said radio receiver, adjustable selecting means at a remote point for establishing a desired station selection condition and indication, a reversible motor directively controlled in response to the adjustment of said selecting means; for directively reversibly adjusting said tuning means, and a signal reprodncer linked to said output circuit and within audible range of said remote point for checking the accuracy of the adjustment of 7 said tuning means. i

In witness whereof, I hereunto subscribe my name this 6th day of October, A. D. 1925.

VVINFRED T. POWELL.

a'bling said series control circuit whereby said last mentioned outlet is given referential control over another outlet, and signal reproducers connectible to". said output circuit through said outlets whereby the adjustment of said tuning means may be "ecked.

16; In a radio receiving sygt a plurality of radio amplifying networks and an 'asso-j 5 ciateddetecting network linked together in 

